title: Examination of the protective effects of heparin and recombinant tissue plasminogen activator (rtPA) in compromised adipocutaneous free flaps in the rat model using intravital video microscopy.
abstract: BACKGROUND
  The purpose of this study was to determine whether the focused delivery of heparin or recombinant tissue plasminogen activator (rtPA) by rinsing accords protective effects which increases the survival of free groin flaps following fatal secondary venous stasis.
  
  
  METHODS
  Free microvascular groin flaps (n = 40) were transplanted to the necks of adult Sprague-Dawley rats 20 hours before the experiment. The study groups (each n = 10 animals) were: No adjunctive treatment (Group I), Ringer's solution (Group II), heparin solution (100 IU/kg, group III) and rtPA (2 mg/kg, group IV), respectively. The flap vein was then clamped for 35 minutes. Intravital video microscopy was applied and flap viability was assessed 14 days later.
  
  
  RESULTS
  Mean flap necrosis was 90% in group I and II, whereas the rate of flap survival was 80% in group III and 60% in group IV, respectively.
  
  
  CONCLUSIONS
  Even though clinical and microvascular flap perfusion parameters in both the rtPA-group and heparin group were initially similar, it has been demonstrated here in our investigations that the flaps treated with heparin showed a higher viability rate. Therefore, we can conclude that the focused delivery of heparin and rtPA resulted in a significantly improved flap salvage.
authors.affiliation: Hand Surgery, Plastic Surgery and Aesthetic Surgery, University Hospital of the Ludwig-Maximilians-University, Campus Grosshadern, Munich, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Wallmichrath
authors.affiliation: Hand Surgery, Plastic Surgery and Aesthetic Surgery, University Hospital of the Ludwig-Maximilians-University, Campus Grosshadern, Munich, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Birk
authors.affiliation: Consultant for Lymphology of the Surgical Clinic Munich Bogenhausen, Munich, Germany.
authors.forename: R G H
authors.initials: RG
authors.lastname: Baumeister
authors.affiliation: Hand Surgery, Plastic Surgery and Aesthetic Surgery, University Hospital of the Ludwig-Maximilians-University, Campus Grosshadern, Munich, Germany.
authors.forename: T O
authors.initials: TO
authors.lastname: Engelhardt
authors.affiliation: Hand Surgery, Plastic Surgery and Aesthetic Surgery, University Hospital of the Ludwig-Maximilians-University, Campus Grosshadern, Munich, Germany.
authors.forename: R E
authors.initials: RE
authors.lastname: Giunta
authors.affiliation: Hand Surgery, Plastic Surgery and Aesthetic Surgery, University Hospital of the Ludwig-Maximilians-University, Campus Grosshadern, Munich, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Frick
mesh_terms: D000328:Adult; D000818:Animals; D058752:Free Tissue Flaps / Q000098:blood supply*; D006493:Heparin / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D018715:Microscopy, Video / Q000379:methods*; D051381:Rats; D017207:Rats, Sprague-Dawley; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use*
chemical_list: D006493:Heparin; D010959:Tissue Plasminogen Activator
keywords: Heparin; I/R; IVM; free flap; groin flap; intravital microscopy; ischemia; microsurgery; rat model; recombinant tissue plasminogen activator; reperfusion; rtPA